Field of the Invention
The present invention relates to a cartridge detachable to an image forming apparatus for forming an image on a recording medium and a method for manufacturing the same.
Description of the Related Art
The present invention relates to an electrophotographic image forming apparatus and a process cartridge (hereinafter referred to as a cartridge) detachable to the electrophotographic image forming apparatus. The electrophotographic image forming apparatus (hereinafter referred to as an image forming apparatus) forms an image on a recording material (recording medium) using an electrophotographic image forming process. An example of the image forming apparatus includes a printer (laser beam printer, light emitting diode (LED) printer, etc.), a copying machine, a facsimile apparatus, a word processor, and a multifunction machine thereof (multifunction printer).
In the image forming apparatus using the electrophotographic image forming process, a process cartridge system is conventionally adopted that allows the cartridge to be detachable to an apparatus main body of the image forming apparatus. The process cartridge system simplifies maintenance of the image forming apparatus by integrating the electrophotographic photosensitive drum (hereinafter referred to as a photosensitive drum) and a process unit acting on the photosensitive drum into the cartridge.
In such a cartridge, cartridge frame members and components constituting the cartridge are sealed therebetween by a plurality of sealing members so that developer (toner) accommodated in the cartridge does not leak out.
In a technique discussed in Japanese Patent Application Laid-Open No. 11-272071, an elastic member, such as an urethane foam, a soft rubber, an elastomer resin, and the like, is used as a sealing member. The sealing member is accurately attached to a coupling portion between frame members and components. However, Japanese Patent Application Laid-Open No. 2001-125465 discusses, for a gap occurring due to the dimensional tolerance of components or variation in the attaching position, a method in which a molten resin, such as a hot melt, is poured into the gap in such a manner that the gap is filled with the resin whereby higher sealing performance is obtained.
In recent years, a method for manufacturing the cartridge has been shifted from a manual method to an automatic (robot) method for the purpose of cost down which is led by increased production efficiency and stability in quality during assembly.